A comprehensive recovery method for indium phosphide waste

Abstract

The present invention belongs to the technical field of non-ferrous metal metallurgy, and specifically relates to a comprehensive recovery method for indium phosphide waste, which is to treat indium phosphide waste by atmospheric pressure oxidation acid leaching process, so that phosphorus generates stable weakly acidic phosphoric acid, and realize efficient leaching of indium phosphide waste; adopt metal replacement process to treat leachate, and recover metallic indium; further treat indium extraction tail liquid by ammonia water neutralization and evaporation crystallization process, and recover aluminum phosphate and ammonium sulfate respectively, so as to realize comprehensive recovery of valuable elements in the system. The technical solution of the present invention has the characteristics of simple operation, low equipment requirements, high efficiency, low energy consumption, low cost, etc., and can realize efficient comprehensive recovery of indium phosphide waste.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal metallurgy, and in particular relates to a comprehensive recovery method for indium phosphide waste. Background Art

[0002] Indium has excellent physical and chemical properties such as good light transmittance, conductivity, fatigue resistance, ductility and corrosion resistance. Therefore, it is widely used in high-tech industries such as solar cells, ITO films, semiconductors and fluorescent materials. Among them, indium phosphide (InP) is a III-V compound semiconductor material with characteristics such as a large bandgap and high electron mobility. With the rapid development of technologies such as 5G communications, navigation satellites and millimeter wave communications, the industry's demand for indium phosphide is increasing day by day.

[0003] However, indium is a rare metal with no independent deposits. It is currently mainly obtained as a by-product of the smelting process of heavy metals such as zinc and lead. Therefore, the recovery of indium from secondary resources will be of great significance to the sustainable development of the indium industry. Indium phosphide has the characteristics of low hardness and strong brittleness, so the scrap rate is high in the production process of InP devices, and the proportion of production waste is as high as about 70%. On the other hand, with the rapid development of the semiconductor industry, indium phosphide semiconductor devices will also be updated and iterated in large quantities, generating a large amount of indium phosphide waste. Therefore, indium phosphide waste will become an important secondary resource of indium, and its comprehensive recovery will be an important supplement to the limited primary resources of indium.

[0004] At present, the research on the recycling of indium phosphide waste is relatively limited.

[0005] A Chinese patent document with publication number CN106319224B discloses a method for recovering indium from indium phosphide waste, using concentrated hydrochloric acid and sodium chlorate as leaching agents to fully dissolve the indium phosphide waste, and further adding zinc powder to the leaching solution to replace it to obtain sponge indium. Although this process can effectively recover metallic indium from indium phosphide waste, the chloride ion leaching system under high acidity conditions not only seriously corrodes the equipment, but also easily volatile hydrogen chloride gas pollutes the production environment; in addition, the thermodynamic driving force of zinc powder replacing indium is limited, and excessive addition of zinc powder will reduce the purity of the sponge indium product, and zinc powder is a controlled reagent that is easy to make explosives, and the production safety risk is relatively high.

[0006] A Chinese patent document with publication number CN106586988B discloses a method for comprehensive recovery of indium and phosphorus from indium phosphide waste, wherein indium phosphide waste powder is placed in a vacuum tube furnace, indium phosphide is decomposed into indium and phosphorus vapor under high temperature and vacuum conditions, and the two are further recovered separately. Although this method can achieve a short-process comprehensive recovery of indium phosphide waste, the production process needs to be carried out under high temperature and vacuum conditions, which not only consumes a lot of energy, but also requires vacuum smelting equipment with high investment costs, resulting in high production costs.

[0007] A Chinese patent document with publication number CN114380323A discloses a method for recovering indium from indium phosphide, wherein indium phosphide powder is uniformly mixed with iron powder, a solid phase reaction is carried out at high temperature, hydrogen chloride gas is further introduced to selectively chlorinate indium to generate volatile indium chloride, and finally InCl3 is recovered by condensation in the gas phase. The indium chloride recovered by this method has a high purity, but the entire recovery process is long, the operation is complicated, the equipment requirements are high, and indium is recovered in the form of indium chloride, which needs to be further processed to obtain a metallic indium product.

[0008] In summary, the existing indium phosphide waste recycling process still has a lot of room for optimization and improvement. It is necessary to further develop a comprehensive indium phosphide waste recycling process technology that is simple to operate, short process, high efficiency, low cost, and environmentally friendly to support the sustainable development of the indium industry. Summary of the invention

[0009] The purpose of the present invention is to overcome the problems of long process flow, low efficiency, high equipment requirements, high production cost, etc. of the existing comprehensive recovery process of indium phosphide waste, and provide a comprehensive recovery method of indium phosphide waste. The process technology of the present invention has the characteristics of simple operation, low equipment requirements, high efficiency, low energy consumption, low cost, etc., and can realize efficient comprehensive recovery of indium phosphide waste.

[0010] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0011] A comprehensive recovery method for indium phosphide waste, which comprises treating indium phosphide waste by a normal pressure oxidation acid leaching process to oxidize phosphorus from -3 valence to +5 valence, generating stable weakly acidic phosphoric acid, and realizing efficient leaching of indium phosphide waste; treating the leachate by a metal replacement process to recover metallic indium; further treating the indium extraction tail liquid by an ammonia water neutralization and evaporation crystallization process to recover aluminum phosphate and ammonium sulfate respectively, and realizing comprehensive recovery of valuable elements in the system.

[0012] Furthermore, the specific operation includes the following steps:

[0013] 1) adding indium phosphide waste powder to a sulfuric acid solution containing hydrogen peroxide, heating the system to a predetermined temperature, and oxidizing phosphorus from -3 valence to +5 valence under mechanical stirring conditions to generate stable weakly acidic phosphoric acid, and indium forms indium sulfate that is easily soluble in water, thereby achieving efficient leaching of indium phosphide waste;

[0014] 2) After the reaction is completed, filtering is performed to achieve solid-liquid separation to obtain a leachate;

[0015] 3) inserting the aluminum plate into the leaching solution to cause a replacement reaction between the metal aluminum and the indium ions to precipitate the metal indium;

[0016] 4) filtering the liquid after the replacement, recovering the sponge indium suspended in the solution, and recovering the sponge indium attached to the surface of the aluminum plate after the replacement reaction; repeatedly washing and drying the recovered sponge indium with deionized water to obtain metallic indium;

[0017] 5) adding ammonia water to the indium extraction tail solution under mechanical stirring conditions to precipitate aluminum phosphate;

[0018] 6) filtering the mixed slurry to achieve solid-liquid separation and obtain filter residue and filtrate; repeatedly washing and drying the filter residue with deionized water to obtain aluminum phosphate powder; evaporating and crystallizing the filtrate to recover ammonium sulfate crystals.

[0019] Furthermore, in step 1), the indium phosphide waste is pre-ball-milled to a particle size of ≤300 μm, the molar ratio of H2O2 and InP is controlled at 4-10:1, the sulfuric acid concentration controls the pH value of the leaching endpoint solution to be controlled at 0-1.5, the mechanical stirring speed is 300-700 r / min, the reaction temperature is 25-95°C, and the reaction time is 1-10 h.

[0020] Furthermore, in step 2), the solid-liquid separation temperature is consistent with the temperature of the oxidative acid leaching process in step 1).

[0021] Furthermore, in step 3), control Al and In 3+ The molar ratio is 2-10:1, the reaction temperature is 55-95°C, and the reaction time is 2-12h.

[0022] Furthermore, in step 4), the filtering temperature is consistent with the temperature of the replacement reaction process in step 3), the recovered sponge indium is washed 4-8 times with deionized water, and dried at 60-100° C. for 24-72 hours to obtain metallic indium.

[0023] Furthermore, in step 5), the amount of ammonia added is controlled to control the pH value of the reaction end point solution to be between 4-6, the mechanical stirring speed is 300-700 r / min, the reaction temperature is 25-95° C., and the reaction time is 1-5 h.

[0024] Furthermore, the solid-liquid separation temperature in step 6) is consistent with the reaction temperature in step 5), the filter residue is washed 4-8 times with deionized water, and dried at 60-100° C. for 24-72 hours to obtain aluminum phosphate powder; the filtrate is evaporated and crystallized to obtain ammonium sulfate crystals.

[0025] The beneficial effects of the present invention are:

[0026] 1. A comprehensive recovery method for indium phosphide waste of the present invention adopts mild sulfuric acid and hydrogen peroxide as leaching agents, which can realize efficient leaching of indium phosphide waste while having low corrosion to equipment, and sulfuric acid is not easy to volatilize and is easy to operate; during the oxidation leaching process, phosphorus is oxidized from -3 valence to the highest valence state +5 valence to generate stable phosphoric acid, and the leaching process does not produce toxic phosphine gas, and only a small amount of oxygen escapes, so the production process is environmentally friendly.

[0027] 2. A comprehensive recovery method for indium phosphide waste of the present invention, after the leaching process is completed, most of the sulfuric acid in the system is converted into weakly acidic phosphoric acid, and the leaching solution is further treated by an aluminum plate replacement process. The aluminum plate will preferentially undergo a replacement reaction with the indium ions in the solution to generate metallic indium, and Al and In 3+ The reaction thermodynamic driving force is large, and the replacement reaction efficiency is high. During the replacement reaction, a small amount of aluminum will react with phosphoric acid, causing a small amount of bubbles to escape from the surface of the aluminum plate, which is conducive to the automatic detachment of the sponge indium generated by the replacement from the surface of the aluminum plate, allowing the fresh unreacted aluminum surface to directly contact the solution, which is conducive to the continuous progress of the reaction and a high indium recovery rate. Excess aluminum plate will not contaminate the sponge indium obtained by replacement, and the purity of the metal indium product is high.

[0028] 3. The comprehensive recovery method of indium phosphide waste of the present invention adds ammonia water to the indium extraction tail liquid for neutralization and recovery to obtain aluminum phosphate, which is an adsorption material with excellent properties and has a wide range of applications in the field of environmental protection; finally, ammonium sulfate crystals are recovered by evaporation and crystallization, which can be used as nitrogen fertilizer in the agricultural field; the entire production process can achieve efficient and comprehensive recovery of valuable elements in the system, with low production cost and good economic benefits.

[0029] Of course, any product implementing the present invention does not necessarily need to achieve all of the above advantages at the same time. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The present invention provides a comprehensive recovery method for indium phosphide waste, wherein the indium phosphide waste is treated by a normal pressure oxidation acid leaching process, phosphorus is made to generate stable weakly acidic phosphoric acid, and efficient leaching of the indium phosphide waste is achieved; the leachate is treated by a metal replacement process to recover metallic indium; the indium extraction tail liquid is further treated by an ammonia water neutralization and evaporation crystallization process to recover aluminum phosphate and ammonium sulfate respectively, and comprehensive recovery of valuable elements in the system is achieved. The technical solution of the present invention has the characteristics of simple operation, low equipment requirements, high efficiency, low energy consumption, low cost, etc., and can achieve efficient and comprehensive recovery of indium phosphide waste.

[0032] The production process of the present invention specifically comprises the following steps:

[0033] 1) adding waste indium phosphide powder ball-milled to less than 300 μm in advance to a sulfuric acid solution containing hydrogen peroxide, wherein the amount of hydrogen peroxide added controls the H2O2 / InP molar ratio to be between 4:1 and 10:1, and the sulfuric acid concentration controls the pH value of the leaching end point solution to be between 0 and 1.5; reacting for 1-10 hours under mechanical stirring conditions of 25-95° C. and 300-700 r / min to oxidize phosphorus from -3 valence to +5 valence to generate stable weakly acidic phosphoric acid, and indium forms indium sulfate that is easily soluble in water, thereby realizing efficient leaching of waste indium phosphide.

[0034] 2) After the reaction is completed, filtering is performed at a temperature of 25-95° C. (consistent with the temperature of the oxidative acid leaching process) to achieve solid-liquid separation to obtain a leachate.

[0035] 3) Insert the aluminum plate into the leaching solution at 55-95℃ for 2-12h, and control the amount of aluminum plate to Al / In 3+ The molar ratio is between 2:1 and 10:1, so that the metal aluminum and the indium ions undergo a replacement reaction to precipitate metal indium.

[0036] 4) filtering the replaced liquid at a temperature of 55-95° C. (consistent with the temperature of the replacement reaction process), recovering the sponge indium suspended in the solution, and recovering the sponge indium attached to the surface of the aluminum plate after the replacement reaction; washing the recovered sponge indium with deionized water for 4-8 times, and further drying at 60-100° C. for 24-72 hours to obtain metallic indium.

[0037] 5) Adding ammonia water to the indium extraction tail solution under mechanical stirring conditions of 25-95° C. and 300-700 r / min for reaction for 1-5 hours, wherein the amount of ammonia water added controls the pH value of the reaction end point solution to be between 4-6, and aluminum phosphate is precipitated.

[0038] 6) Filter the mixed slurry at a temperature of 25-95° C. (consistent with the temperature of the neutralization precipitation aluminum phosphate reaction process) to achieve solid-liquid separation and obtain filter residue and filtrate; wash the filter residue with deionized water for 4-8 times, and further dry it at 60-100° C. for 24-72 hours to obtain aluminum phosphate powder; evaporate and crystallize the filtrate to obtain ammonium sulfate crystals.

[0039] The present invention is further described below in conjunction with specific embodiments.

[0040] Example 1

[0041] A comprehensive recovery method of indium phosphide waste in this embodiment specifically comprises the following steps:

[0042] 1) adding indium phosphide waste powder ball-milled to less than 300 μm in advance into a sulfuric acid solution containing hydrogen peroxide, wherein the amount of hydrogen peroxide added controls the H2O2 / InP molar ratio to be 4:1, and the sulfuric acid concentration controls the pH value of the leaching end point solution to be 0; reacting for 10 hours under mechanical stirring conditions at a temperature of 25° C. and a rotation speed of 300 r / min, oxidizing phosphorus from -3 valence to +5 valence to generate stable weakly acidic phosphoric acid, and indium forms indium sulfate that is easily soluble in water, thereby realizing efficient leaching of indium phosphide waste.

[0043] 2) After the reaction is completed, the mixture is filtered at 25° C. to separate the solid from the liquid and obtain a leachate.

[0044] 3) Insert the aluminum plate into the leaching solution at 55°C for 12 hours, and control the amount of aluminum plate to achieve the desired Al / In ratio. 3+ The molar ratio is 2:1, so that the metal aluminum and indium ions undergo a replacement reaction to precipitate metal indium.

[0045] 4) filtering the replaced liquid at 55° C. to recover the sponge indium suspended in the solution, and at the same time recovering the sponge indium attached to the surface of the aluminum plate after the replacement reaction; washing the recovered sponge indium with deionized water for 4 times, and further drying at 60° C. for 72 hours to obtain metallic indium.

[0046] 5) Add ammonia water to the indium extraction tail solution under mechanical stirring conditions of 25° C. and 300 r / min for 5 hours. The amount of ammonia water added is controlled to control the pH value of the solution at the reaction end point to be 4, and aluminum phosphate is precipitated.

[0047] 6) filtering the mixed slurry at 25° C. to achieve solid-liquid separation and obtain filter residue and filtrate; washing the filter residue with deionized water for 4 times, and further drying at 60° C. for 72 h to obtain aluminum phosphate powder; evaporating and crystallizing the filtrate to obtain ammonium sulfate crystals.

[0048] The method of this embodiment was used to analyze the recovery rate and purity of metallic indium by aqua regia dissolution combined with inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the recovery rate of metallic indium was 96.8% and the purity of metallic indium was 99.5%.

[0049] Example 2

[0050] A comprehensive recovery method of indium phosphide waste in this embodiment specifically comprises the following steps:

[0051] 1) adding indium phosphide waste powder ball-milled to less than 300 μm in advance into a sulfuric acid solution containing hydrogen peroxide, wherein the amount of hydrogen peroxide added controls the H2O2 / InP molar ratio to be 10:1, and the sulfuric acid concentration controls the pH value of the leaching end point solution to be 1.5; reacting for 1 hour under mechanical stirring conditions of a temperature of 95° C. and a rotation speed of 700 r / min, oxidizing phosphorus from -3 valence to +5 valence to generate stable weakly acidic phosphoric acid, and indium forms indium sulfate that is easily soluble in water, thereby realizing efficient leaching of indium phosphide waste.

[0052] 2) After the reaction is completed, the mixture is filtered at 95° C. to achieve solid-liquid separation and obtain an leaching solution.

[0053] 3) Insert the aluminum plate into the leaching solution at 95℃ for 2h, and control the Al / In 3+ The molar ratio is 10:1, so that the metal aluminum and indium ions undergo a replacement reaction to precipitate metal indium.

[0054] 4) filtering the replaced liquid at 95° C. to recover the sponge indium suspended in the solution, and at the same time recovering the sponge indium attached to the surface of the aluminum plate after the replacement reaction; washing the recovered sponge indium with deionized water for 8 times, and further drying at 100° C. for 24 hours to obtain metallic indium.

[0055] 5) Add ammonia water to the indium extraction tail solution under mechanical stirring conditions of 95° C. and 700 r / min for 1 hour. The amount of ammonia water added is controlled to control the pH value of the solution at the reaction end point to be 6, and aluminum phosphate is precipitated.

[0056] 6) filtering the mixed slurry at 95° C. to achieve solid-liquid separation and obtain filter residue and filtrate; washing the filter residue with deionized water for 8 times, and further drying at 100° C. for 24 hours to obtain aluminum phosphate powder; evaporating and crystallizing the filtrate to obtain ammonium sulfate crystals.

[0057] The method of this embodiment was used to analyze the recovery rate and purity of metallic indium by aqua regia dissolution combined with inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the recovery rate of metallic indium was 97.1% and the purity of metallic indium was 99.8%.

[0058] Example 3

[0059] A comprehensive recovery method of indium phosphide waste in this embodiment specifically comprises the following steps:

[0060] 1) adding indium phosphide waste powder ball-milled to less than 300 μm in advance into a sulfuric acid solution containing hydrogen peroxide, wherein the amount of hydrogen peroxide added controls the H2O2 / InP molar ratio to be 5.5:1, and the sulfuric acid concentration controls the pH value of the leaching end point solution to be 0.3; reacting for 8 hours under mechanical stirring conditions of a temperature of 45° C. and a rotation speed of 400 r / min, oxidizing phosphorus from -3 valence to +5 valence to generate stable weakly acidic phosphoric acid, and indium forms indium sulfate that is easily soluble in water, thereby realizing efficient leaching of indium phosphide waste.

[0061] 2) After the reaction is completed, the mixture is filtered at 45° C. to achieve solid-liquid separation and obtain an leaching solution.

[0062] 3) Insert the aluminum plate into the leaching solution at 65℃ for 10h, and control the Al / In 3+ The molar ratio is 4:1, so that the metal aluminum and indium ions undergo a replacement reaction to precipitate metal indium.

[0063] 4) filtering the replaced liquid at 65° C. to recover the sponge indium suspended in the solution, and at the same time recovering the sponge indium attached to the surface of the aluminum plate after the replacement reaction; washing the recovered sponge indium with deionized water for 5 times, and further drying at 70° C. for 60 hours to obtain metallic indium.

[0064] 5) Add ammonia water to the indium extraction tail solution under mechanical stirring conditions of 45°C and 400 r / min for 4 hours. The amount of ammonia water added is controlled to control the pH value of the solution at the reaction end point to be 4.5, and aluminum phosphate is precipitated.

[0065] 6) filtering the mixed slurry at 45° C. to achieve solid-liquid separation and obtain filter residue and filtrate; washing the filter residue with deionized water for 5 times, and further drying at 70° C. for 60 h to obtain aluminum phosphate powder; evaporating and crystallizing the filtrate to obtain ammonium sulfate crystals.

[0066] The method of this embodiment was used to analyze the recovery rate and purity of metallic indium by dissolution in aqua regia combined with inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the recovery rate of metallic indium was 96.2% and the purity of metallic indium was 99.6%.

[0067] Example 4

[0068] A comprehensive recovery method of indium phosphide waste in this embodiment specifically comprises the following steps:

[0069] 1) adding waste indium phosphide powder ball-milled to less than 300 μm in advance into a sulfuric acid solution containing hydrogen peroxide, wherein the amount of hydrogen peroxide added controls the H2O2 / InP molar ratio to be 7:1, and the sulfuric acid concentration controls the pH value of the leaching end point solution to be 0.8; reacting for 6 hours under mechanical stirring conditions of a temperature of 60° C. and a rotation speed of 500 r / min, oxidizing phosphorus from -3 valence to +5 valence to generate stable weakly acidic phosphoric acid, and forming indium sulfate that is easily soluble in water, thereby realizing efficient leaching of waste indium phosphide.

[0070] 2) After the reaction is completed, the mixture is filtered at 60° C. to achieve solid-liquid separation and obtain a leachate.

[0071] 3) Insert the aluminum plate into the leaching solution at 75℃ for 8 hours, and control the amount of aluminum plate to achieve the ratio of Al / In 3+ The molar ratio is 6:1, so that the metal aluminum and indium ions undergo a replacement reaction to precipitate metal indium.

[0072] 4) filtering the replaced liquid at 75° C. to recover the sponge indium suspended in the solution, and at the same time recovering the sponge indium attached to the surface of the aluminum plate after the replacement reaction; washing the recovered sponge indium with deionized water for 6 times, and further drying at 80° C. for 48 hours to obtain metallic indium.

[0073] 5) Add ammonia water to the indium extraction tail solution under mechanical stirring conditions of 60° C. and 500 r / min for 3 hours. The amount of ammonia water added is controlled to control the pH value of the solution at the reaction end point to be 5, and aluminum phosphate is precipitated.

[0074] 6) filtering the mixed slurry at 60° C. to achieve solid-liquid separation and obtain filter residue and filtrate; washing the filter residue with deionized water for 6 times, and further drying at 80° C. for 48 hours to obtain aluminum phosphate powder; evaporating and crystallizing the filtrate to obtain ammonium sulfate crystals.

[0075] The method of this embodiment was used to analyze the recovery rate and purity of metallic indium by dissolution in aqua regia combined with inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the recovery rate of metallic indium was 97.5% and the purity of metallic indium was 99.8%.

[0076] Example 5

[0077] A comprehensive recovery method of indium phosphide waste in this embodiment specifically comprises the following steps:

[0078] 1) adding indium phosphide waste powder ball-milled to less than 300 μm in advance into a sulfuric acid solution containing hydrogen peroxide, wherein the amount of hydrogen peroxide added controls the H2O2 / InP molar ratio to be 8.5:1, and the sulfuric acid concentration controls the pH value of the leaching end point solution to be 1.2; reacting for 3 hours under mechanical stirring conditions of 80° C. and 600 r / min, oxidizing phosphorus from -3 valence to +5 valence to generate stable weakly acidic phosphoric acid, and indium forms indium sulfate that is easily soluble in water, thereby realizing efficient leaching of indium phosphide waste.

[0079] 2) After the reaction is completed, the mixture is filtered at 80° C. to achieve solid-liquid separation and obtain a leachate.

[0080] 3) Insert the aluminum plate into the leaching solution at 85℃ for 5 hours, and control the amount of aluminum plate to achieve the ratio of Al / In 3+ The molar ratio is 4:1, so that the metal aluminum and indium ions undergo a replacement reaction to precipitate metal indium.

[0081] 4) filtering the replaced liquid at 85° C. to recover the sponge indium suspended in the solution, and at the same time recovering the sponge indium attached to the surface of the aluminum plate after the replacement reaction; washing the recovered sponge indium with deionized water for 7 times, and further drying at 90° C. for 36 hours to obtain metallic indium.

[0082] 5) Add ammonia water to the indium extraction tail solution under mechanical stirring conditions of 80° C. and 600 r / min for 2 h. The amount of ammonia water added is controlled to control the pH value of the solution at the reaction end point to be 5.5, and aluminum phosphate is precipitated.

[0083] 6) filtering the mixed slurry at 80° C. to achieve solid-liquid separation and obtain filter residue and filtrate; washing the filter residue with deionized water for 7 times, and further drying at 90° C. for 36 hours to obtain aluminum phosphate powder; and evaporating and crystallizing the filtrate to obtain ammonium sulfate crystals.

[0084] The method of this embodiment was used to analyze the recovery rate and purity of metallic indium by aqua regia dissolution combined with inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the recovery rate of metallic indium was 98.1% and the purity of metallic indium was 99.6%.

[0085] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A comprehensive recovery method for indium phosphide waste, characterized in that: The waste indium phosphide is treated by atmospheric pressure oxidation acid leaching process, so that phosphorus is oxidized from -3 valence to +5 valence, stable weakly acidic phosphoric acid is generated, and efficient leaching of the waste indium phosphide is achieved; the leachate is treated by metal replacement process to recover metallic indium; the indium extraction tail liquid is further treated by ammonia neutralization and evaporation crystallization process to recover aluminum phosphate and ammonium sulfate respectively, so as to achieve comprehensive recovery of valuable elements in the system; The specific operation includes the following steps: 1) adding indium phosphide waste powder to a sulfuric acid solution containing hydrogen peroxide, heating the system to a predetermined temperature, and oxidizing phosphorus from -3 valence to +5 valence under mechanical stirring conditions to generate stable weakly acidic phosphoric acid, and indium forms indium sulfate that is easily soluble in water, thereby achieving efficient leaching of indium phosphide waste; 2) After the reaction is completed, filtering is performed to achieve solid-liquid separation to obtain a leachate; 3) inserting the aluminum plate into the leaching solution to cause a replacement reaction between the metal aluminum and the indium ions to precipitate the metal indium; 4) filtering the liquid after the replacement, recovering the sponge indium suspended in the solution, and recovering the sponge indium attached to the surface of the aluminum plate after the replacement reaction; repeatedly washing and drying the recovered sponge indium with deionized water to obtain metallic indium; 5) adding ammonia water to the indium extraction tail solution under mechanical stirring conditions to precipitate aluminum phosphate; 6) filtering the mixed slurry to achieve solid-liquid separation and obtain filter residue and filtrate; repeatedly washing and drying the filter residue with deionized water to obtain aluminum phosphate powder; evaporating and crystallizing the filtrate to recover ammonium sulfate crystals.

2. A comprehensive recovery method for indium phosphide waste according to claim 1, characterized in that: In step 1), the indium phosphide waste is pre-ball-milled to a particle size of ≤300 μm, the molar ratio of H2O2 and InP is controlled at 4-10:1, the sulfuric acid concentration controls the pH value of the leaching endpoint solution to be controlled at 0-1.5, the mechanical stirring speed is 300-700 r / min, the reaction temperature is 25-95°C, and the reaction time is 1-10 h.

3. A comprehensive recovery method for indium phosphide waste according to claim 2, characterized in that: In step 2), the solid-liquid separation temperature is consistent with the oxidation acid leaching process temperature in step 1).

4. The method for comprehensive recovery of indium phosphide waste according to claim 1, characterized in that: In step 3), control Al and In 3+ The molar ratio is 2-10:1, the reaction temperature is 55-95°C, and the reaction time is 2-12h.

5. A comprehensive recovery method for indium phosphide waste according to claim 4, characterized in that: In step 4), the filtration temperature is consistent with the temperature of the replacement reaction process in step 3), and the recovered sponge indium is washed 4-8 times with deionized water and dried at 60-100° C. for 24-72 hours to obtain metallic indium.

6. The method for comprehensive recovery of indium phosphide waste according to claim 1, characterized in that: In step 5), the amount of ammonia added is controlled to control the pH value of the reaction end point solution to be between 4 and 6, the mechanical stirring speed is 300-700 r / min, the reaction temperature is 25-95° C., and the reaction time is 1-5 h.

7. A comprehensive recovery method for indium phosphide waste according to claim 6, characterized in that: The solid-liquid separation temperature in step 6) is consistent with the reaction temperature in step 5), the filter residue is washed 4-8 times with deionized water, and dried at 60-100° C. for 24-72 hours to obtain aluminum phosphate powder; the filtrate is evaporated and crystallized to obtain ammonium sulfate crystals.